U.S. patent number 7,232,428 [Application Number 10/148,360] was granted by the patent office on 2007-06-19 for medical cock.
This patent grant is currently assigned to Nippon Sherwood Medical Industries, Ltd.. Invention is credited to Kazuhiro Abe, Kazuaki Inukai, Hideyuki Makino, Susumu Miyasaka.
United States Patent |
7,232,428 |
Inukai , et al. |
June 19, 2007 |
Medical cock
Abstract
A sealable access stopcock includes a valve body having a
switching part formed in a valve shaft thereof for switching from
one flow passage to another; and a main body having an internal
chamber in which the valve shaft of the valve body is rotatably
fitted, and a plurality of tributary tubes each having a lumen
extending therethrough, the lumen opening on a side wall of the
internal chamber; the valve body being rotated to selectively bring
the lumens into communication with one another through the
switching part and thereby switch flow of an infusion fluid from
one flow passage to another. A switching channel is provided in the
form of an arcuate groove in the switching part of the valve shaft
to extend along the circumferential surface thereof.
Inventors: |
Inukai; Kazuaki (Tokyo,
JP), Miyasaka; Susumu (Tokyo, JP), Abe;
Kazuhiro (Tokyo, JP), Makino; Hideyuki (Tokyo,
JP) |
Assignee: |
Nippon Sherwood Medical Industries,
Ltd. (Tokyo, JP)
|
Family
ID: |
14237412 |
Appl.
No.: |
10/148,360 |
Filed: |
November 29, 1999 |
PCT
Filed: |
November 29, 1999 |
PCT No.: |
PCT/JP99/06633 |
371(c)(1),(2),(4) Date: |
May 25, 2002 |
PCT
Pub. No.: |
WO01/39826 |
PCT
Pub. Date: |
June 07, 2001 |
Current U.S.
Class: |
604/248 |
Current CPC
Class: |
A61M
39/02 (20130101); A61M 39/223 (20130101) |
Current International
Class: |
A61M
5/00 (20060101) |
Field of
Search: |
;604/248,246,247,256,167.01,167.05,167.03,284 ;128/912
;137/625.4,625.46,625.47,625.41 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Lucchesi; Nicholas
Assistant Examiner: Stigell; Theodore J.
Attorney, Agent or Firm: Muramatsu & Associates
Claims
The invention claimed is:
1. A cock for medical use, comprising: a valve body having a
switching part formed in a valve shaft thereof for switching from
one flow passage to another by operation of a handle; and a main
body in the form of a bottomed cylinder having an internal chamber
in which the valve shaft of the valve body is rotatably fitted, and
three tributary tubes each having a lumen extending therethrough,
the lumen opening on a side wall of the internal chamber; the valve
body being rotated through the handle to alternately bring the
lumens into communication with one another through the switching
part and thereby switch flow of an infusion fluid from one flow
passage to another; wherein one of the tributary tubes is a patient
side tributary tube for connection to the patient and other two
tributary tubes are source side tributary tubes for connection to
infusion sources; wherein one of the source side tributary tubes is
made much shorter than the other source side tributary tube and the
patient side tributary tube; and wherein the long source side
tributary tube is arranged in line with the patient side tributary
tube; wherein the short source side tributary tube is arranged at
an angle of about 90.degree. with respect to the other tributary
tubes, and the short source side tributary tube is filled with a
septum so as to substantially eliminate dead space in the tributary
tube; and wherein the switching part is located right under the
lumen of the short source side tributary tube, and wherein the
switching part comprises a switching valve which has a cross
section consisting of a semicircular closure portion along the
circumferential surface of the valve shaft and a semicircular core
portion with a smaller radius than the semicircular closure portion
so as to form a switching channel in a form of an arcuate groove in
the valve shaft.
2. The cock for medical use according to claim 1, wherein a slit is
formed in the septum for allowing passage of a needle.
3. The cock for medical use according to claim 1, wherein
limitation means is provided for limiting the range of rotation of
the valve body.
4. The cock for medical use according to claim 1, wherein click
means is provided for stopping rotation of the valve body in a
discrete manner.
5. The cock for medical use according to claim 1, wherein the
switching channel is so formed that the valve body can be rotated
even when a needle of a syringe or a connector is exposed in the
switching channel.
Description
TECHNICAL FIELD
The present invention relates to a sealable access stopcock. More
particularly, the present invention relates to a sealable access
stopcock including a plurality of tributary tubes for connecting an
infusion tube and a switching part for switching from one flow
passage to another. Such a stopcock is provided on a flow passage
of infusion fluid to allow mixed infusion of an additional drug
solution by switching the flow passage, or a syringe may be
connected to the tributary tube through its needle to inject
another drug solution or to collect a blood sample by switching
from one tributary tube to another as desired.
BACKGROUND ART
3-way stopcocks are known as one type of such medical instruments.
A 3-way stopcock includes three tributary tubes that are separated
from one another by an angle of, for example, 90.degree.. FIGS.
11(a) and 11(b) shows construction of the conventional 3-way
stopcock while FIGS. 12(a) 12(b) and 13(a) 13(b) each illustrates
one application of the conventional 3-way stopcock, with (a) in
each figure being a plan view and (b) being a cross-section. FIG.
14 shows one application of a construction shown in FIGS. 13(a) and
13(b).
In FIGS. 11(a) and 11(b), a reference numeral 1 denotes a 3-way
stopcock, a reference numeral 2 denotes a main body thereof, and
reference numerals 5, 6, and 7 each indicates a tributary tube. The
tributary tubes 5, 6, and 7 are separated from one another by
90.degree.. A reference numeral 8 denotes a thread formed at an end
of each of the tributary tubes 5 and 7 whereas a reference numeral
9 denotes a tapered portion formed on one end of the tributary tube
6. A cap is normally placed over each of the threads 8.
Reference numerals 12, 13, and 14 indicate a valve body, a valve
shaft, and a handle, respectively. A reference numeral 16 denotes a
T-shaped switching conduit formed through the valve shaft 13. The
valve shaft 13 of the valve body 12 is fitted into the main body 2.
The flow of infusion fluid is switched from one flow passage to
another by turning the valve body 12 through the handle 14 so that
the switching conduit 16 communicates with the tributary tubes 5,
6, and 7 in turn. An infusion tube, connected to a source of
infusion fluid, is connected to the tributary tube 5 through the
thread 8 while another tube, connected to a blood vessel, is
connected to the tapered portion 9 of the tributary tube 6.
Referring to FIGS. 12 through 14, reference numerals 10, 20, 22,
23, and 50 denote a septum, a cylinder of a syringe (injection
cylinder), a connector, a blunt needle, and a plug (infusion plug),
respectively. The plug 50 is connected to the tributary tube 7
through the thread 8. Referring to FIGS. 13(a) and 13(b), a 3-way
stopcock 1 includes a septum 10 similar to the one shown in FIGS.
12(a) and 12(b). The septum 10 is placed in a relatively short
tributary tube 7. Structure of the connector 22 including the blunt
needle 23 will be described later. In FIGS. 12(b) and 13(b), a
reference numeral 40 indicates air bubbles. The area containing the
air bubbles represents an internal space of the tributary tube 7
(i.e., dead space).
The conventional 3-way stopcock 1 as shown in FIG. 11 is arranged
between a patient and a source of infusion fluid so that when the
valve body 12 is turned, the flow of infusion fluid is selectively
switched from one flow passage to another. However, while the
tributary tubes 5 and 6 are in communication with each other for
administration of a drug solution, the tributary tube 7, not in
use, is left unattended without any sanitary measure being taken
except for the above-mentioned cap placed over the thread 8.
Accordingly, there is a risk of microbial contamination from the
end region of the tributary tube 7. Also, there is a concern that
the drug solution remaining within the tributary tube 7, which
radially extends away from the main body 2, provides an ideal
breeding ground for bacteria.
Among various drug solutions, intravenous hyperalimentation may
provide an optimum growth medium for bacteria. In particular, the
end region of the syringe 20 is subjected to the possibility of
contamination through contact with the surrounding atmosphere or
linens each time the syringe 20 is attached to, or removed from,
the tributary tube 7 of the 3-way stopcock 1. In addition, the deep
hollow construction of the tributary tube 7 makes it difficult to
wipe off the remaining solution and sterilize the tube, which often
results in insufficient sanitary procedures. For this reason, once
bacteria enter the tributary tube 7, it is extremely difficult to
prevent their growth.
An approach devised by medical practitioners in an effort to cope
with these problems involves use of the 3-way stopcock 1 in
conjunction with the plug 50 as shown in FIGS. 12(a) and 12(b).
Each of the constructions shown in FIGS. 12(a) and 12(b) and in
FIGS. 13(a) and 13(b) includes the septum 10 on one end of the
tributary tube 7 for isolation from the surrounding atmosphere and
thus preventing entrance of bacteria while the tributary tube 7 is
not in use. During use of the tributary tube 7, the septum 10 may
be punctured by a syringe needle for, for example, injecting an
additional drug solution into the main drug solution. In case of
the 3-way stopcock 1 as shown in FIGS. 12(a) and 12(b), the plug 50
is attached to the end of the tributary tube 7. The two components
connected to one another have an increased length and, as a result,
the volume of the drug solution that the tube can contain is
increased by a corresponding amount. This increase in the volume of
the flow passage of infusion fluid leads to formation of a dead
space in which a small amount of the high concentration drug
solution remains. As a result, dosage of the drug solution may fall
short, or the drug solution may be wasted. Furthermore, if
administration of an additional drug solution follows, the residual
solution may be added to the additional solution, which results in
an excessive dosage or a mixture of the added drug solution and the
residual solution being administered to patients.
In general, when it is desired to collect blood samples during this
type of infusion process, the infusion is interrupted to allow
blood to flow back to upstream of the 3-way stopcock 1. Once the
inrushing blood has filled adjacent area of the 3-way stopcock 1,
the septum 10 of the 3-way stopcock 1 is punctured by a syringe
needle to collect the undiluted blood. After collection of the
blood samples, the infusion fluid is again allowed to flow in the
positive direction through the flow passage of infusion fluid to
push out the blood toward the blood vessel and clean the flow
passage of infusion fluid.
However, the dead space as shown in FIGS. 12(a) and 12(b) impedes
collection of blood samples through the septum 10 of the 3-way
stopcock 1 using a syringe. This is a particularly serious problem
in the case of arterial infusion, in which blood collection is
essential. Further, the increased passage length increases
generation of air bubbles 40 and makes it considerably difficult to
remove the bubbles. In addition, such a dead space makes the
deaeration process difficult during the brimming process when the
infusion passage is filled with infusion fluid in the first place.
Furthermore, the large dead space can provide an ideal breeding
ground for bacteria that enter the tube by accident.
In comparison, the 3-way stopcock 1 as shown in FIGS. 13(a) and
13(b) has a short tributary tube 7 and mitigates the problems
associated with the dead space as described in reference to FIGS.
11 and 12. In such a construction, however, when the syringe 20 or
the connector 22 is connected for side injection or mixed infusion
of a drug solution, the needle of the syringe or the connector 22
that punctures the septum 10 and projects into the T-shaped
switching conduit 16 interrupts switching operation of the infusion
passage. In order to permit switching of the flow passage of
infusion fluid, the syringe or the connector 22 must be pulled out
each time the flow passage is switched. As a result, not only the
advantage of the 3-way stopcock that the infusion passage can be
freely switched is lost, but each insertion/removal of the syringe
20 or the connector 22 also increases the likelihood of bacteria
entrance. This is also the case with the 3-way stopcock as shown in
FIG. 14.
SUMMARY OF THE INVENTION
The present invention has been devised to address the
above-mentioned problems associated with the prior art.
Accordingly, it is an objective of the present invention to provide
a sealable access stopcock that facilitates switching of the flow
passage of infusion fluid as well as removal of air bubbles, has
good isolation property for preventing microbial contamination, and
is easy to operate to introduce a drug solution into a blood vessel
while preventing stagnation of the drug solution.
According to the present invention, there is provided a sealable
access stopcock including: a valve body having a switching part
formed in a valve shaft thereof for switching from one flow passage
to another; and a main body having an internal chamber in which the
valve shaft of the valve body is rotatably fitted, and a plurality
of tributary tubes each having a lumen extending therethrough, the
lumen opening on a side wall of the internal chamber; the valve
body being rotated to selectively bring the lumens into
communication with one another through the switching part and
thereby switch flow of an infusion fluid from one flow passage to
another. This sealable access stopcock being characterized in that
a switching channel in the form of an arcuate groove is formed in
the switching part of the valve shaft to extend along the
circumferential surface thereof.
According to the present invention, there is also provided a
sealable access stopcock including: a valve body having a switching
part formed in a valve shaft thereof for switching from one flow
passage to another and a knob; and a main body having an internal
chamber in which the valve shaft of the valve body is rotatably
fitted, and a plurality of tributary tubes each having a lumen
extending therethrough, the lumen opening on a side wall of the
internal chamber; the valve body being rotated through the knob to
selectively bring the lumens into communication with one another
through the switching part and thereby switch flow of an infusion
fluid from one flow passage to another. This sealable access
stopcock is characterized in that at least one of the plurality of
tributary tubes is a short tube having a septum, and a switching
channel in the form of an arcuate groove is formed in the switching
part of the valve shaft to extend along the circumferential surface
thereof.
According to the present invention, there is also provided a
sealable access stopcock including: a valve body having a switching
part formed in a valve shaft thereof for switching from one flow
passage to another and a handle; and main body in the form of a
bottomed cylinder having an internal chamber in which the valve
shaft of the valve body is rotatably fitted, and three tributary
tubes each having a lumen extending therethrough, the lumen opening
on a side wall of the internal chamber; the valve body being
rotated through the handle to alternately bring the lumens into
communication with one another through the switching part and
thereby switch flow of an infusion fluid from one flow passage to
another. This sealable access stopcock being characterized in that
the three tributary tubes are formed by connecting a short tube
having a septum to an elongate tube at the center of the elongate
tube so that the short tube forms an angle of about 90.degree. with
respect to the elongate tube, and a switching channel in the form
of an arcuate groove is formed in the switching part of the valve
shaft to extend along the circumferential surface thereof.
According to the present invention, there is also provided a
sealable access stopcock in which a switching valve is formed in
the remaining part of the switching part other than the switching
channel. The switching valve consists of a core having a circular
cross-section and an umbrella-shaped closure portion extending
along the circumferential surface thereof.
According to the present invention, there is also provided a
sealable access stopcock in which a slit is formed in the septum
for allowing passage of a needle.
According to the present invention, there is also provided a
sealable access stopcock in which limitation means is provided for
limiting the range of rotation of the valve body.
According to the present invention, there is also provided a
sealable access stopcock in which click means is provided for
stopping rotation of the valve body in a discrete manner.
For example, the stopcock of the present invention is used in the
following manner. First, the handle of the valve body is turned to
close the lumen of the tributary tube that is connected to a
patient. Using a double thread and a tapered portion, an infusion
tube is then connected to each of the two tributary tubes that form
a main conduit. The infusion tube that is upstream of the other is
connected to a source of infusion fluid. The valve body is then
turned through the handle to open the lumen of the tributary tube
on the side of a discharge port. As the lumen of the discharge-side
tributary tube is opened, the infusion fluid reaches an end of the
infusion tube. The infusion tube filled with the infusion fluid to
the end thereof is then connected to an indwelling needle placed in
the blood vessel of the patient. Through the main conduit, a
primary drug solution is introduced into the body of the patient
(blood vessel) via the switching channel of the valve shaft. The
infusion fluid flows through the main conduit Rm as it smoothly
passes through the switching channel, which is formed as an arcuate
groove. Upon mixed infusion or side injection, the flow of infusion
fluid can be switched from one flow passage to another by rotating
the valve body through the handle while a sharp needle or a blunt
needle is placed through the septum.
The present invention not only prevents entry of bacteria into the
infusion fluid during administration of the primary drug solution
through the main conduit but also significantly facilitates
processes including collection of blood samples and removal of air
bubbles because of the reduced length of the flow passage. Also,
the present invention allows the valve body to be rotated during
mixed infusion or side injection to switch from one flow passage to
another with the sharp needle or the blunt needle placed through
the septum and remaining within the switching channel. Accordingly,
a highly operable sealable access stopcock is achieved. Further,
the present invention, which includes limitation means for limiting
the range of rotation of the valve body as well as click means for
stopping rotation of the valve body in a discrete manner, provides
a safe, manageable sealable access stopcock.
The present invention achieves a sealable access stopcock that
facilitates switching of the flow passage of infusion fluid as well
as removal of air bubbles, has good isolation property for
preventing microbial contamination, and is easy to operate to
introduce a drug solution into a blood vessel while preventing
stagnation of the drug solution.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) and 1(b) are schematic diagrams showing construction of
first embodiment of the present invention.
FIG. 2 is a cross-section taken along the line X--X in FIG.
1(a).
FIGS. 3(a) 3(e) are schematic diagrams showing construction of a
valve body of the first embodiment.
FIGS. 4(a) 4(c) are schematic diagrams showing an example of
operation of the first embodiment.
FIG. 5 is an explanatory view showing an advantageous aspect of the
first embodiment.
FIGS. 6(a) and 6(b) are schematic diagrams showing another
advantageous aspect of the first embodiment.
FIGS. 7(a) and 7(b) are schematic diagrams showing an example of
switching operation of the first embodiment.
FIG. 8 is a cross-section showing major components of a second
embodiment of the present invention.
FIG. 9 is an enlarged cross-section taken along the line Z--Z in
FIG. 8.
FIG. 10 is an enlarged perspective view showing major components of
a third embodiment.
FIGS. 11(a) and 11(b) are schematic diagrams showing construction
of a conventional 3-way stopcock.
FIGS. 12(a) and 12(b) are schematic diagrams showing one
application of the conventional 3-way stopcock.
FIGS. 13(a) and 13(b) are schematic diagrams showing another
application of the conventional 3-way stopcock.
FIG. 14 is an explanatory view showing one application of the
construction shown in FIG. 13.
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment
FIGS. 1(a) and 1(b) are schematic diagrams showing construction of
a first embodiment of the present invention, where FIG. 1(a) is a
frontal view; and FIG. 1(b) is a cross-section thereof. FIG. 2 is a
cross-section taken along the line X--X in FIG. 1(a). FIGS. 3(a)
3(e) are schematic diagrams showing construction of a valve body
according to the first embodiment, where FIG. 3(a) is a top view;
FIG. 3(b) is a plan view; FIG. 3(c) is a frontal view; FIG. 3(d) is
a right-side view; and FIG. 3(e) is a cross-section taken along the
line Y--Y in FIG. 3(a).
Referring to FIGS. 1 and 2, a reference numeral 1 denotes a
sealable access stopcock and a reference numeral 2 denotes a main
body formed as a bottomed cylinder. The main body 2 is made of a
transparent resin material such as polycarbonate (PC) and
polyethylene terephthalate (PET) and PET/PC alloys. A reference
numeral 3 denotes an internal chamber centered on a central axis
O--O. A reference numeral 4 indicates an annular groove formed on
the inner periphery of the internal chamber 3 along the
circumferential direction.
Reference numerals 5, 6, and 7 denote tributary tubes that are
separated from one another by an angle of about 90.degree. and
extend radially outward from the central axis O--O. Reference
numerals 5a, 6a, and 7a are lumens of the respective tributary
tubes, each of which opens into the internal chamber 3 of the main
body 2. The tributary tubes 5 and 6 each have an elongate shape and
are aligned with each other to form a main conduit Rm through which
blood or a drug solution flows. The tributary tube 7 is much
shorter than the tributary tubes 5 and 6, and forms a branch
conduit Rb that intersects the main conduit Rm. Reference numerals
8 and 9 denote a double thread and a tapered portion for connection
formed on ends of the tributary tubes 5 and 6, respectively, while
a reference numeral 10 indicates a septum disposed in the tributary
tube 7. Since the tributary tube 7 is very short, the inner space
thereof is filled with the septum 10 as shown by the hatches in
FIG. 1(b). The septum 10 is an elastic body formed from materials
such as synthetic rubber and has a slit 11 through which a blunt or
a sharp needle is passed upon addition of a drug solution in a side
injection or a mixed injection process or collection of blood
samples.
Reference numerals 12 and 13 denote a valve body and a valve shaft,
respectively. The valve shaft 13 forms a cylindrical portion below
the valve body 12. Reference numerals 14a and 14b denote handles,
which are formed above the valve shaft 13 and extend horizontally
in opposite directions. The valve body 12 and the main body 2 are
integrated with each other and together form the sealable access
stopcock 1. The valve body 12 is made of a plastic material such as
polyethylene and polypropylene and, unlike the main body 2, is
colored by an opaque color resin. A short projection 14c is formed
to intersect the horizontally extending handles 14a and 14b such
that the valve body 12 has a similar contour to the main body 2
when viewed in a plan view.
The structure of the valve body 12 is shown in its particularity in
FIG. 3(a) through FIG. 3(e) in partial views. A reference numeral
15 denotes a switching part that forms a disk portion in the valve
shaft 13 and faces the lumens 5a through 7a of the main body 2. The
cross-section of the switching part 15 is shown in FIG. 3(e). As
can also be seen from FIG. 1(b), FIGS. 4(b) 4(c) and FIG. 5, the
switching part 15 is located right under the lumen 7a of the short
tributary tube 7. A reference numeral 16 denotes a switching
channel of the switching part 15 while a reference numeral 17
denotes a switching valve forming the remainder of the element. As
shown, the switching channel 16 is formed as an arcuate groove
extending along a circumferential surface so that the cross-section
of the switching valve 17 consists of a circular core 17a and an
umbrella-shaped closure portion 17b. The circular core 17a that is
formed about the central axis O--O at a lower end of the switching
valve 17 serves to make smooth the flow of infusion fluid and
reinforce the switching part 15 of the valve shaft 13. The angle
.theta. of the switching channel 16 substantially corresponds to
the angle over which the lumens 5a through 7a are arranged.
A reference numeral 18 denotes a ridge 18 formed about the valve
shaft 13 and corresponds to the groove 4. Reference numerals 19
denote arrow signs placed on the handles 14a and 14b and the
projection 14c, respectively, with each sign directing each of the
three directions. The arrow on the projection 14c is aligned with
the central line of the switching channel 16. The valve shaft 13 is
inserted into the internal chamber 3 from above and is placed
therewithin in a rotatable, liquid-tight manner. With the valve
shaft 13 placed in the internal chamber 3, the switching channel 16
and the switching valve 17 face the lumens 5a through 7a on the
respective same radii. The valve shaft 13 is positioned in the
internal chamber 3 by the ridge 18 engaging the groove 4. The
engagement of the ridge 18 with the groove 4 prevents the valve
shaft 13 from exiting from the internal chamber 3 and serves to
maintain the liquid-tightness against the internal chamber 3. Thus,
the valve body 12 can be turned through the handles 14a and 14b to
open or close communication among the lumens 5a through 7a via the
switching channel 16 so that the flow passage is switched between
the main conduit Rm and the branch conduit Rb.
Next, the flow of a primary drug solution through the stopcock of
the first embodiment having the construction described thus far is
described with reference to the accompanying drawings.
First, the handles 14a and 14b are placed at a position as
indicated by the double-dotted line in FIG. 4(a). When the handles
14a and 14b are in this position, the closure portion 17b of the
switching valve 17 closes the opening of the lumen 6a in the
internal chamber 3 as shown in FIG. 4(b). An infusion tube (not
shown) is connected to each of the tributary tubes 5 and 6 by
making use of the double thread 8 and the tapered portion 9. The
infusion tube connected to the tributary tube 5 is connected on the
other end to a source of infusion fluid such as an ampul. When the
valve body 12 is rotated clockwise by 90.degree. through the
handles 14a and 14b from the position indicated by the
double-dotted line to a position indicated by the solid line in
FIG. 4(a), communication of the lumen 6a of the tributary tube 6 is
established.
When communication of the lumen 6a is opened, the infusion fluid
flows through the infusion tube connected to the tributary tube 6
to an end thereof. The infusion tube filled with the infusion fluid
to its end is connected to an indwelling needle placed in a blood
vessel of a patient. A primary drug solution is infused into the
body of the patient (blood vessel) through the main conduit Rm that
connects the tributary tube 5 to the tributary tube 6 via the
switching channel 16 of the valve shaft 13. The flow of the primary
drug solution is indicated by an arrow in FIG. 4(c). As indicated
by the arrow, the infusion fluid flows through the main conduit Rm
as it smoothly passes through the arcuate switching channel 16.
Since the inner space of the tributary tube 7 is filled with the
septum 10 as noted above, the septum 10 isolates the inside of the
sealable access stopcock 1 from the surrounding atmosphere during
infusion and prevents entry of bacteria into the primary drug
solution flowing through the main conduit Rm. Upon side injection
of a small amount of a high concentration drug solution, the lumen
6a is also closed by the switching valve 17. In this state, a sharp
needle 21 of a syringe is passed through the slit 11 of the septum
10 toward the central axis of the internal chamber 3. Once the
needle is introduced, the handles 14a and 14b are rotated by
180.degree. in the same manner as described above to open
communication of the lumen 6a and thus form the branch conduit Rb
as shown in FIG. 5 connecting the tributary tube 7 to the tributary
tube 6 for injection. A plunger of the syringe 20 is then pushed
thereinto to push out the small amount of the high concentration
drug solution from the sharp needle 21 exposed in the switching
channel 16. In this manner, the small amount of the high
concentration drug solution is directly injected from the switching
channel 16 into the tributary tube 6 in one shot. As a result, the
side-injected solution flows through the arcuate switching channel
16 and is introduced into the blood vessel of the patient in a
smooth and quick fashion. In this regard, because the tributary
tube 7 is very short, no dead space is formed within the tributary
tube 7. Subsequently, the handles 14a and 14b are returned to the
position as shown in FIG. 4(b) to close the lumen 6a, and the sharp
needle 21 is pulled out from the septum 10. This completes the side
injection process.
When it is desired to continuously introduce another drug solution
during infusion of the primary drug solution, a connector 22 such
as those shown in FIGS. 6 and 7 are used. Reference numerals 23,
24, 25, and 26 denote a blunt needle (or cannula) of the connector
22, a connector tube placed about the blunt needle 23, a connection
slot, and a double thread, respectively. Though not specifically
shown, the connection slot 25 is formed as a key-shaped slot, and
an engage pin (not shown), which projects from the outer periphery
of the tributary tube 7 at a position corresponding to the
connection slot 25, is placed therethrough. By placing the
connector tube 24 over the outer periphery of the tributary tube 7
with the engage pin engaging the connection slot 25 and slightly
rotating the connector tube 24, the connector 22 is locked against
the main body 2, providing removable connection thereto.
The lumen 6a is also closed when it is necessary to continuously
introduce another drug solution for mixed infusion. The connector
22 is connected to the tributary tube 7 in the above-described
manner as shown in FIGS. 6 and 7. Once the connector 22 is
connected to the tributary tube 7, the blunt needle 23 is passed
through the slit 11 of the septum 10. The handles 14a and 14b are
then positioned parallel to the tributary tubes 5 and 6 to open the
lumen 6a. As a result, the secondary solution, supplied through an
infusion tube connected to the connector 22, is introduced through
the blunt needle 23 into the primary solution flowing through the
main conduit Rm and is mixed therewith in the switching channel 16.
From the switching channel 16, the mixed solution flows through the
lumen 6a of the tributary tube 6 and then the infusion tube and is
continuously introduced into the body of the patient (blood
vessel). The drug solution, as it is discharged from the blunt
needle 23, is readily mixed into the primary solution within the
switching channel 16 to be administered. Again, no dead space is
formed within the tributary tube 7.
When it is desired to collect blood samples, the handles 14a and
14b are turned to close the lumen 6a and thus interrupt the mixed
infusion through the blunt needle 23. A sharp needle 21 of a
syringe is passed through the slit 11 of the septum 10 in the same
manner as described in reference to FIG. 5. Blood is sucked through
the tributary tube 6 and collected into the syringe 20 without
being diluted with the infusion solution by pulling a plunger of
the syringe 20. Once collection of blood samples is finished,
infusion fluid is passed to push the blood back into the blood
vessel and clean the flow passage. In this manner, blood samples
can be collected by means of the sharp needle 21 directly inserted
into the switching channel 16 of the valve shaft 13 without having
the blood diluted with the infusion fluid since no dead space is
formed within the tributary tube 7.
When air bubbles form in the flow passage of infusion fluid, a
syringe, having air bubbles removed from its injection cylinder, is
mounted with its needle piercing through the septum 10. Then, the
plunger of the syringe 20 is pulled by the knob to suck the air
bubbles into the sharp needle 21. In this manner, air bubbles
present in the infusion fluid can be readily removed. Further, the
smooth flow of the infusion fluid through the arcuate switching
channel 16 substantially reduces air bubble generation, simplifying
the deaeration process.
As set forth, the sealable access stopcock 1 according to the first
embodiment includes the short tributary tube 7 having the septum 10
for isolating from the surrounding environment and serves to switch
the flow of infusion fluid from one flow passage to another by
means of the switching channel 16, which is formed as an arcuate
groove extending along the circumferential surface of the valve
shaft 13. Not only does this construction prevent entry of bacteria
into the infusion fluid during administration of the primary drug
solution through the main conduit Rm, but it also significantly
facilitates processes including collection of blood samples and
removal of air bubbles because of the reduced length of the flow
passage. Also, this construction allows the handles 14a and 14b to
be turned during mixed infusion or side injection to switch from
one flow passage to another with the sharp needle 21 or the blunt
needle 23 placed through the septum 10 and remaining within the
switching channel 16. Accordingly, a highly operable sealable
access stopcock 1 can be provided.
Second Embodiment
FIG. 8 is a cross-section of one construction of a second
embodiment of the present invention showing major components
thereof while FIG. 9 is an enlarged cross-section taken along the
line Z--Z in FIG. 8.
In FIGS. 8 and 9, a reference numeral 30 denotes a limitation tube
placed about the valve shaft 13 of the valve body 12, a reference
numeral 31 denotes a limitation projection projecting from the
inner surface of the limitation tube, and a reference numeral 32
denotes an arcuate cutout formed along the outer periphery of the
main body 2 at the top end thereof. The angle of the cutout 32
formed on the main body 2 is substantially the same as the
above-described angle .theta. of the arch of the switching channel
16. The limitation projection 31 on the valve body 12 engages the
cutout 32.
When the valve body 12 is turned through the handles 14a and 14b to
switch from one flow passage to another, the limitation projection
31 slides within the arcuate cutout 32. The valve body 12 can be
rotated through the handles 14a and 14b in the direction indicated
by an arrow A until the limitation projection 31 comes into contact
with a left limit 32a of the cutout 32 whereas it can be rotated in
the direction B until the limitation projection 31 comes into
contact with a right limit 32b. In other words, rotation of the
valve shaft 13 is limited within the range of angle .theta.. This
construction prevents the sharp needle 21 or the blunt needle 23
projecting in the switching channel 16 from bending or breaking. In
this manner, rotation over the angle .theta. can easily be limited
since part of the limitation tube 30, which has a larger diameter
than the valve shaft 13, serves to limit the rotation.
Third Embodiment
Referring to FIG. 10, major components of a third embodiment are
shown in an enlarged perspective view. This embodiment employs a
construction featuring a click function for causing the valve shaft
to snap into position at different positions, in addition to the
above-described function of the second embodiment for limiting the
rotation angle.
In FIG. 10, a reference numeral 33 denotes a slit formed on either
side of the limitation projection 31, which was described in the
second embodiment above. A reference numeral 34 denotes a
semicircular protrusion. The slits 33 allow the limitation
projection 31 to resiliently move in the radial direction with
respect to the central axis O--O. Accordingly, the protrusion 34
can be resiliently displaced in the radial direction.
Though not shown, the cutout 32 of the main body 2 shown in FIG. 9
includes three axial grooves each having a semicircular
cross-section that corresponds to the protrusion 34. The grooves
are formed at three different positions. As the valve body 12 is
rotated through the handles 14a and 14b, the protrusion 34 snaps
into each of the semicircular grooves and is stopped in a discrete
manner. The three discrete click positions at which the protrusion
34 comes to stop correspond to respective positions of the closure
portion 17b of the switching valve 17 for closing the lumens 5a,
6a, and 7a.
The third embodiment is advantageous in that it can provide a
sealable access stopcock 1 that features two functions of limiting
rotation of the valve body 12 and stopping the valve body 12 in a
discrete manner.
While in the above-described embodiment, the three tributary tubes
to form the main conduit are separated from one another by
90.degree., the three tributary tubes may be spaced apart by equal
or unequal distances and are arranged within 180.degree. range.
Also, a greater or fewer number of the tributary tubes may be
provided. Further, while in the example shown, two handles are
provided on both sides of the valve shaft, a conventional
construction or a cantilever-type construction may also be
employed, or in some cases, a dial-shaped knob may be employed.
Also, while the valve shaft has a cylindrical shape with a uniform
diameter, it may have a multi-step construction. Constructions
other than those described in reference to the above embodiments
may also be contemplated in terms of shapes of the main body or
other aspects of the present invention.
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